Footnotes renumbering automatically
I am working on a book which has four or five main chapters, but the footnotes number sequentially from 1 to 450 or so through the whole book, rather than starting at 1 again in each chapter (yes, I know, we tried to persuade the editors not to do this...). I divided the original InDesign (version 6) file up into chapters and created a book file. I set the footnote numbering in each chapter to begin from the correct number rather than automatically starting at 1. The footnote numbers in the InDesign files were all fine. However, when I exported to epub I lose this and the footnotes in each chapter start from 1 again.
I'd done a fair amount of work on the file in Sigil before I realised this so I'm a bit loathe to go back to InDesign, but I'd rather do this than have to renumber 300-odd footnotes manually in about four places for each footnote.
Is there any way i can fix this in the export process from InDesign, or within Sigil? I can't see any relevant options in the epub export options.